Process for preparing an alternating copolymer of butadiene and acrylonitrile

ABSTRACT

A process for preparing an alternating copolymer of butadiene and acrylonitrile which comprises contacting butadiene and acrylonitrile in liquid phase with a catalyst, said catalyst comprises the first component selected from the group consisting of an aluminum halide and a zinc halide, a vanadium compound as the second component and the third component selected from the group consisting of an organo-aluminum compound, an organozinc compound and an organolithium compound. The alternating copolymers obtained by this invention are rubber-like in character and are useful in the field of rubber, plastics industries, etc.

United States Patent Kawasaki et al.

[ June 27, 1972 [54] PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF BUTADIENE AND ACRYLONITRILE [72] V Inventors: Aklhlro Kawasaki, Ichihara; HiroaIriUeda, Chiba; Masanobu Tanlguchi, Ichihara, all

of Japan [73] Assignee: Maruzen Petrochemical Co., Ltd., Tokyo,

. Japan [22] Filed: April 16, 1970 211 Appl. No.: 29,300

[30] Foreign Application Priority Data April 28, I969 Japan ..44/33036 May 31, 1969 May 3 l, 1969 May 31, I969 Japan ..44/42086 [52] US, Cl ..260/82.5 {5 1] Int. Cl ...C08d 1/14, C08d 3/04, C08d 3/06 [58] Field at Search ..260/82.5

[56] References Cited FOREIGN PATENTS OR APPLICATIONS 1,487,211 5/1967 France ..260/82.5

1,123,724 8/1968 GreatBritain "260/825 OTHER PUBLICATIONS Symposium of Japanese Chemical Fiber Institute October 1968, No.26, p. 83- 96 Furakawa et al.

Bull. Insti. Chem. Res, Kyoto Univ., Vol. 47, No. 3, pages 222- 238; Furakawa et al., May 1969.

Primary ExaminerJoseph L. Schofer Assistant Examiner-William F. I-Iamrock Attorney-Flynn & Frishauf 57 ABSTRACT 9 Claims, No Drawings PROCESS FOR PREPARING AN ALTERNATING COPOLYMER F BUTADIENE AND ACRYLONITRILE This invention relates to a new process of polymerizing butadiene and acrylonitrile and more particularly to a new process of preparing an alternating copolymer of butadiene and acrylonitrile which shows high elasticity. The alternating copolymer is easily soluble in some kinds of organic solvents. It shows also higher rubber-like elasticity than the corresponding random copolymer. it is useful in the field of rubber, plastics industries, etc.

Recently, Furukawa et. al. (J. Polymer Sci. B7, 47 (1969); Nippon Kagaku Sen-i Kenkyu Sho Koenkai, Osaka, Oct., 1968) reported the process for preparing an alternating copolymer of butadiene and acrylonitrile showing rubber-like elasticity. The system comprising of ethylaluminum dichloride acrylonitrile complex and vanadium (V) oxychloride was used as the catalyst.

As far as the inventors know, with the exception of Furukawa et al., there is no prior art in connection with the process for preparing an alternating copolymer of butadiene and acrylonitrile.

The object of the present invention is to provide new catalytic systems for the production of alternating copolymer of butadiene and acrylonitrile in high yield.

In accordance with this invention, we have found that by using either one of the catalyst system of I. an aluminum halide a vanadium compound an organoaluminum compound,

2. an aluminum halide a vanadium compound an organozinc compound,

3. an aluminum halide a vanadium compound an organolithium compound,

4. a zinc halide a vanadium compound an organoaluminum compound,

5. a zinc halide a vanadium compound an organozinc compound and 6. a zinc halide a vanadium compound an organolithium compound, an alternating copolymer of butadiene and acrylonitrile can be produced in high yield.

The aluminum halides used as the first component of the present invention may be defined by the formula AlX wherein X is chlorine, bromine or iodine. The zinc halides which form the other first component of the present invention may be defined by the formula ZnX, wherein X is chlorine, bromine or iodine. The vanadium compounds which form the second component of the catalyst of this invention are vanadium (V) oxyalkoxide compounds having the general formula of OV(OR),,X -n wherein R is a hydrocarbon radical such as alkyl radical, aryl radical or cycloalkyl radical, X is chlorine, bromine or iodine and n is l, 2 or 3; vanadium (IV) halide having the general formula of VX wherein X is chlorine, bromine or iodine; vanadium (V) oxyhalide having the general formula of VOX wherein X is chlorine, bromine or iodine; vanadium complex such as dicyclopentadienyl vanadium, vanadium oxydiacetylacetonate, vanadium triacetylacetonate, vanadium cyclopentad enyl tetracarbonyl; etc. The organoaluminum compounds which form the third component of the catalyst of this invention may be defined by the formula AlR,,X;, wherein R is a hydrocarbon radical such as alkyl radical, aryl radical or cycloalkyl radical, X is chlorine, bromine or iodine and n is l,- 1.5, 2 or 3. The organozinc compounds which form the other third component of the catalyst of this invention may be defined by the formula Z,,R wherein R is a hydrocarbon radical such as alkyl radical, aryl radical or cycloalkyl radical. The organolithium compounds which form the other third component of this invention may be defined by the formula LiR wherein R is a hydrocarbon radical such as alkyl radical, aryl radical or cycloalkyl radical. The quantity of the three components of this invention may be varied over a wide range. However, in the catalyst system of an aluminum halide, a vanadium compound and an organoaluminum compound, the molar ratio of an aluminum halide to an organoaluminum compound AlX ,IAIR,,)L,,) is critical. In the preferred embodiment the molar ratio of an aluminum halide to an organoaluminum compound having the general formula of AIR, should be equal to 2 or higher than 2 (AlXJAlR 2 2), the molar ratio of an aluminum halide to an organoaluminum compound having the general formula of AlRgX should be equal to l or higher than 1 (AIX IAIR X 2 l) and the molar ratio of an aluminum halide to an organoaluminum compound having the general formula of AIR X should be equal to l or higher than 1 a/ r un Hydrocarbons, such as heptane, octane, isooctane, benzene, toluene, etc.; chlorinated hydrocarbons, such as methylene chloride, ethylene chloride, tetrachloroethane, tetrachloroethylene, ethylchloride, trichloroethylene, trichloroethane, etc.; or a mixture of such diluents are used as diluent in preparing the catalyst. The diluent should be pretreated to remove harmful impurities which may be ofien contained therein. The presence of moisture, sulphur, sulphur-containing compounds and oxygen would act as harmful impurities. In actual practice, it is preferred that such impurities should not be present in the diluent or in the monomer which is to be copolymerized.

The preparation of the new alternating copolymer of butadiene and acrylonitrile is carried out by contacting a mixture of the monomers in liquid phase with the catalyst system described above. The copolymerization reaction is generally carried out in the presence of a liquid organic diluent. Suitable diluents that can be used for the copolymerization are hydrocarbons, such as heptane, octane, isooctane, benzene, toluene, etc.; chlorinated hydrocarbons, such as methylene chloride, ethylene chloride, tetrachloroethane, tetrachloroethylene, ethylchloride, trichloroethylene, trichloroethane, etc.; or a mixture of such diluents. The

diluent should also be pretreated to remove harmful impurities which may be contained therein.

The temperature of the copolymerization process can be varried over a wide range, generally from l00 C. to +60 C. and preferably from -78 C. to +40 C. Sufiicient pressure is employed to keep the monomers in liquid condition regardless Whether a diluent is present in the reaction mixture or not.

In general, the molar ratio of butadiene to acrylonitrile in the initial monomer composition will be from 20:80 to 80:20 and more usually be 50:50.

After the copolymerization is complete, the reaction product is separated from the reaction tube and treated to separate the diluent and unreacted monomer. The alternate copolymer is then treated to remove the catalyst residues, said treatment may comprise washing with an acidified methanol. The acid which is used to acidify methanol is a mineral acid such as hydrochloric acid. Thereafter the alternate copolymer may be washed with methanol several times and may be dried under vacuum.

The composition of thecopolymer obtained by the process of the present invention according to elementary analysis substantially agrees well with the calculated value for the 1:] copolymer of butadiene and acrylonitrile. The copolymerization reaction gave 1:1 copolymer over a wide range of initial monomer composition and also independently of polymerization time. The microstructure of butadiene unit in the copolymer was all trans-configuration. The NMR spectrum of the copolymer was shown to be very different from that of the conventional ultra high nitrile (acrylonitrile content 48 mole percent random copolymer of butadiene and acrylonitrile prepared by the prior art. Two strong peaks were observed at 7.7'lf and 7.89f in the NMR spectrum of the conventional ultra high nitrile random copolymer. On the other hand in the NMR spectrum of the copolymer in this invention only one strong peak appeared at 7.7lf in this region. This means that block sequence of butadiene-butadiene is not substantially included. Consequently, each fact mentioned above supports the assumption that the present copolymer should be an alternating copolymer of butadiene and acrylonitrile.

The alternating copolymer is easily soluble in chloroform, acetone and dimethylformamide at room temperature.

The invention will be illustrated with reference to the following Examples.

Ref. l. Moreover, in practice, the reactions described above does not proceed completely in the catalyst system and unreacted aluminum chloride should be remained in the system. These results mean that the catalyst system in Ref. 1 is quite 5 different from the catalyst system in Exp. No. 4. As can be EXAMPLE I seen in Exp. No. l Exp. No. 4, by varying the molar ratio of In Exp. No. l 7 and Ref. 6 of Table l, the usual dry, air- 'r chlonde i g z ziggfifizfi ggr: free technique was employed and 2.0 milliliters toluene, 25.0 mg g ig a v g d In Ref 6 the millimoles acrylonitrile, a mixture of varying amounts of alu- 10 1" I. t a. 5 ig g T s i i minum chloride and 1.0 milliliter methylene chloride and mo at m o a um c y varying amounts of triethylaluminum solution in toluene (1.0 molar solution) were put successively in a 25 milliliters glass EXAMPLE 2 bottle at room temperature. Then the bottle was held in a low Employing the usual, dry, air-free technique, 3.0 milliliters temperature bath at 78 C. and varying amounts of vanadium toluene, varying amounts of aluminum chloride, varying compound and 25.0 millimoles butadiene were put successiveamounts of triethylaluminum solution in heptane (2.0 molar ly into the bot le als emp oying the Usual, y, air-free solution) and 25.0 millimoles acrylonitrile were put succestechnique. Thereafter the bottle was sealed and the monomers l l i a 25 millili r la b l t o m t m ratu Th were allowed to copolymerize at 25 C- for 17 h -H' Th the bottlev was held in a low temperature bath at 78 C. and results were summ rize In T l l 20 0.02 millimole vanadium compound and 25.0 millimoles bun R the usual, y. e teehmque was e p y tadiene were put successively into the bottle also employing and 2.0 milliliters toluene, 25.0 m1ll1moles acrylonitrile and h l, d i -f t h i u The e f th bot l was 1.0 milhllter diethylaluminum monochloride or ethylalul d d h monomers were allowed to copolymerize at minum dichloride solution in toluene 1.0 molar solution) or a C, for 17 h Th results were summarized i T bl 2,

TABLE 2 Alternating copolymer Ylold per Yield per Catalyst aluminum organoalumiatom in tho. 1111111 00111- Exp AeCo; AcEt; Vanadium c0111- Yield catalyst pound (g./ No. (1111110l.) (n1111ol.) pound (11111101.) (g.) (g./n11110l.) 11111101.) 1 0.8 0.2 V0003 0. 02 0. s0 0. 80 4. 00 2 0.8 0.2 V0(0Et).1. 0. 02 1. 28 1.2% 0.40 Ref. 1... 0.5 0.5 VO(OEt)3 0. 02 0. 55 0.55 1.10 mixture of 1.0 millimole aluminum chloride and 1.0 milliliter EXAMPLE 3 methylene chloride were put successively in a 25 milliliters glass bottle at room temperature. Then the bottle was held in a low temperature bath at 78 C. and 0.02 millimole vanadium (V) oxychloride and 25.0 millimoles butadiene were put successively into the bottle also employing the usual, dry, air-free technique. Thereafter the bottle was sealed and the monomers were allowed to copolymerize at 25 C. for 17 hours.

Ref. 1 and Ref. 2 show the results obtained by the method reported by Furukawa et al. and the activity of the catslyst system in Ref. l is higher than that of the catalyst system in Ref. 2.

The molar ratio of aluminum chloride to triethylaluminum in Exp. No. 4 is 2/1 and 0.99 millimole ethylaluminum dichloride may be produced if the following reactions proceed completely;

0.66A1Cl l- 0.33A1Et 0.33A1Ol l- 0.33AlEtCh 0.33AlEt2Cl 0.66AlEtClz 0.33AlEl2Ch 7 r 0.9941EtCl2 I On the other hand the activity of the catalyst system in Exp. No. 4 is apparently higher than that of the catalyst system in TABLE 1 5 acrylonitrile were put successively in a Employing the usual, dry, air-free technique, 2.0 milliliters toluene, varying amounts of diethylaluminum monochloride solution in toluene 1.0 molar solution) and a mixture of varying amounts of aluminum chloride and 25.0 millimoles acrylonitrile were put successively in a 25 milliliters glass bottle at room temperature. Then the bottle was held in a low temperature bath at 78 C and 0.04 milliliter vanadium (V) oxychloride solution in toluene (1.0 molar solution) and 25.0 millimoles butadiene were put successively into the bottle also employing the usual, dry, air-free technique. Thereafter the bottle was sealed and the monomers were allowed to copolymerize at 25 C. for 16 hours. The results are summarized in Table 3.

In Ref. 1 and Ref. 2, the usual, dry, employed and 2.0 milliliters toluene, minum dichloride or diethyl-aluminum in toluene (1.0 molar solution) air free technique was 1.0 milliliter ethylalumonochloride solution and 25.0 millimoles 25 milliliters glass bottle at room temperature. Then the bottle was held in a low temperature bath 78 C. and 0.04 milliliter vanadium (V) oxychloride solution in toluene (1.0 molar solution) and 25.0

Alternating copolymer Catalysts Yield per 211- Yield per orlumlnum ganoalumi- AeEtCez or atom on the num com- Exp AeCm AeEtzCe AcEt Vanadium compound Yield catalyst (g./ pound (g./ N 0 (mmol.) (n1mol.) (1111nol.) (m1nol.) (g.) mmol.) mmol.) 1. 0 0 1 VOC03 0. 02 0.88 0. 8. 80

4 0. G6 0. 02 0. 7G 0. 77 2. 30 Rcf.1 AOEtC0z. 1.0 0.02 0.55 0.55 0.55 Rol.2 AvEtzCeu 0. 02 0.13 0.13 0.13 R01. 3. l. 0. 02 0.18 O. 18 Ref. =1. l. 0. 38 0. 32 1. R0l.5. l. 0.07 0.07 llvf. t l. 0 0. 02 0. 61 0.31 0. 61 5. 1.0 0.2 V()(()Et)3 0.02 1.72 1. 43 8.60 (i 1.0 0.2 VO(()EL).1 0. 10 1.36 1.13 6.80 7 l. 0 0. 2 \"(=1c:1c)3. 0. 0i 1. 15 0 00 5, 75

millimoles butadiene were put successively into the bottle also employing the usual, dry, air-free technique. Thereafter the bottle was sealed and the monomers were allowed to copolymerize at 25 C. for 16 hours.

If the following reaction proceeds completely in the catalyst 5 system in Exp. No. 4; 0.5 AlCl 0.5 AlEt C1 A1EtC1 1 .0 millimole ethylaluminum dichloride should be produced in the catalyst system. On the other hand the activity of the catalyst system in Exp. No. 4 is higher than that of the catalyst 1 7 EXAMPLE 5 The usual, dry, air-free technique was employed and varying amounts of toluene, 25.0 millimoles acrylonitrile and a mixture of 8.0 millimoles zinc chloride and 1.0 milliliter methylene chloride and 0.2 milliliter organoaluminum compound solution in toluene (1.0 molar solution) were put successively in a milliliters glass bottle at room temperature. Then the bottle was held in a low temperature bath at 78 C. and varying amounts of vanadium compound and 25.0 millimoles butadiene were put successively into the bottle also employing the usual, dry, air-free technique. Thereafter the bottle was sealed and the monomers were allowed to copolymerize at 25 C. for 17 hours. The results are summarized in Table 5.

TAB LE 6 No. 4 is quite different from the catalyst system in Ref. 2.

TABLE 3 Alternating copolynicr Yicld per Yield pet Catalyst aluminum organoaluatom in the minum com- Exp. AeCe; AeEtiCez or VOCe; Yield catalyst pound (g./

No. (mmoL) (ii1m01.) (mmol (g.) (g. /mmo1.) nimol.)

0. 5 AoEtzCe. O. 4 0. 04 0. 85 0. 85 2. 13

0. 75 AeEt2Ce 0. 25 0. O4 1. 17 1. 17 4. 08

0. AcEtzCe. O. 1 0. 04 0. 75 0. 75 7. 50

0. 5 AOEt2C0. 0. 5 0. 04 0. 83 0. 83 1. 66

. AoEt2C0 1.0 0.04 0.15 0.15 0.15

R01. 2 AeEtCc2 1. 0 0. 04 0. 53 0. 53 0. 53

EXAMPLE 4 EXAMPLE 6 The usual, dry, air-free technique was employed and 2.0

milliliters toluene, varying amounts of ethyl-aluminum dichloride solution in toluene (1.0 molar solution) and a mixture of varying amounts of aluminum chloride and 25.0 millimoles acrylonitrile were put successively in a 25 milliliters glass bottle at room temperature. Then the bottle was held in a low temperature bath at 78 C. and 0.04 milliliter vanadium (V) oxychloride solution in toluene (1.0 molar solution) and 25.0 millimoles butadiene were put successively into the bottle also employing the usual, dry, air-free technique.

The usual, dry, air-free technique was employed and 3.0 milliliters toluene, a mixture of 25.0 millimoles acrylonitrile and 1.0 millimole aluminum chloride and varying amounts of organometallic compound were put successively in a 25 milliliters glass bottle at room temperature. Then the bottle was held in a low temperature bath at 78 C. and 0.02 millimole vanadium compound and 25.0 millimoles butadiene were put successively into the bottle also employing the usual, dry, airfree technique. Thereafter the bottle was sealed and the monomers were allowed to copolymerize at 25 C. for 17 Thereafter the bottle was sealed and the monomers were allowed to copolymerize at 25 C. for 16 hours. The results are 55 hours. The results are summarized in Table 6.

summarized in Table 4. TABLE 6 In Ref. 1 and Ref. 2, the usual, dry, air-free technique was r a employed and 2.0 milliliters toluene, 1.0 milliliter ethylalu- Catalysts Yield of minum dichloride solution in toluene (1.0 molar solution) or A )rganometa11- V d altel'lilatillg 3 1C (301111301111 3113 111111 Colll- C0110 \'111Gl' 1.0 m llimole aluminum chloride and 25.0 millimoles Exp NO (mmoL) (mmol') pound (mmoL) acrylonitrile were put successively in a 25 milliliters glass bot- 7 C O tle at 25 C. Then the bottle was sealed and the monomers i8 55: 8:: 2 863:: 8:8 8:33 were allowed to copolymerize at 25 C. for 16 hours. i. 0 ZIlEtc... 0. 4 V(acac) 0 02 8. i;

The catalyst activity in Exp. No. l or Exp. No. 2 is apparently higher than that in Ref. 1.

TABLE 4 Alternating copolymer Yield per Yield per Catalysts aluminum organeatom in the aluminum A1013 A1E12C12 V0011 Yield catalyst compound Exp. No (mmoL) (mmoL) (iiiiiioL) (g (gJmnioL) (g./mmol.)

1.. 0. 5 (1. 5 (1.0-1 0.113 0. 93 1. 8(1 2.. 0. 0 l1. 3 0.01 0. 71 (1. 72 2. 37 R01. l 1.0 0.01 O. 53 0.53 0 53 l l) U. 02 U. 18 0. 18

EXAMPLE 7 ture bath at C. and 0.02 millimole vanadium compoundand 25.0 millimoles butadiene were put successively into the bottle also employing the usual, dry, air-free technique. Thereafter the bottle was sealed and the monomers were allowed to copolymerize at 25 C. for 17 hours. The results were summarized in Table 7.

TABLE 7 wherein the molar ratio of component A to component C is at least 2 when component C is vAlR the molar ratio of component A to component C is at least I when component C is AIR,X, and the molar ratio of component A to component C is at least 1 when component C is AlR X, 5

2. A process of claim 1 wherein said component A is an aluminum halide and said component C is a compound having the formula AlR 3. A process of claim 1 wherein said component A is an aluminum halide and said component C is a compound having the formula AlR X.

v 4. A process of claim 1 wherein said component A is an aluminum halide and said component C is a compound having the formula AIR, X

Diluent Catalysts Yield of Methylene chloride (ml.)

ZnE t: (mrnoL) Vanadium compound (mmol.)

alternating copolyme What we claim is:

1. A process for preparing a l: l copolymer of butadiene and acrylonitrile having alternating butadiene and acrylonitrile units, which comprises contacting butadiene and acrylonitrile in non-aqueous liquid phase with a catalyst, said catalyst comprising component A, component B and component C wherein component A is an aluminum halide having the formula AlX or a zinc halide having the formula ZnX wherein X is chlorine, bromine or iodine; component B is selected from the group consisting of OV(OR),,X VX VOX dicyclopentadienyl vanadium, vanadium cyclopentadienyl tetracarbonyl, vanadium triacetylacetonate and vanadium oxydiacetylacetonate wherein R is an alkyl, an aryl or a cycloalkyl radical, X is chlorine, bromine or iodine and n is l, 2 or 3,

and component C is AlR,,X;, ZnR, or UK wherein R is an alkyl, an aryl or a cycloalkyl radical, X is chlorine, bromine or iodine and n is l, 1.5, 2 or 3,

5. A process of claim 1 wherein said component A is an aluminum halide and said component C is a compound having the formula Auzx,

6. A process of claim 1 wherein said contact is carried out in the presence of a diluent selected from the group consisting of a hydrocarbon, chlorinated hydrocarbon and a mixture thereof.

7. A process of claim 1 wherein the molar ratio of butadiene to acrylonitrile in the initial monomer composition is within a range of from 20:80 to :20.

8. A process of claim 1 wherein said contact is conducted at a temperature is of from 1 00 C. to +60 C.

9. A process of claim 1 wherein said contact is carried out at a temperature of from l00 C. to +60 C. and in the presence of a diluent selected from the group consisting of a hydrocarbon, chlorinated hydrocarbon and a mixture thereof. 

2. A process of claim 1 wherein said component A is an aluminum halide and said component C is a compound having the formula AlR3.
 3. A process of claim 1 wherein said component A is an aluminum halide and said component C is a compound having the formula AlR2X.
 4. A process of claim 1 wherein said component A is an aluminum halide and said component C is a compound having the formula AlR1 5X1
 5. 5. A process of claim 1 wherein said component A is an aluminum halide and said component C is a compound having the formula AlRX2.
 6. A process of claim 1 wherein said contact is carried out in the presence of a diluent selected from the group consisting of a hydrocarbon, chlorinated hydrocarbon and a mixture thereof.
 7. A process of claim 1 wherein the molar ratio of butadiene to acrylonitrile in the initial monomer composition is within a range of from 20:80 to 80:20.
 8. A process of claim 1 wherein said contact is conducted at a temperature is of from -100* C. to +60* C.
 9. A process of claim 1 wherein said contact is carried out at a temperature of from -100* C. to +60* C. and in the presence of a diluent selected from the group consisting of a hydrocarbon, chlorinated hydrocarbon and a mixture thereof. 